[syncfusion_charts] Cancel long-press zoom

[DrNiels]

Use case

Sometimes, you want to drag a chart but accidently remain in place too long and start a zoom operation by accident or just decide that you want to cancel the zoom operation while you're at it. However, you can't.

Proposal

Making the zoom operation via long-press cancelable would be nice, either by providing a hook, so a developer can introduce a cancel operation that fits their app, or by providing a default like pressing Escape.